1. Field of the Invention
The invention pertains to the field of surgical devices. More particularly, the invention pertains to tracking of surgical objects placed in a human or animal body.
2. Description of Related Art
Surgical practice often requires placing surgical objects in the human body that may remain in place for at least a portion of the duration of a surgical procedure. These objects include, but are not limited to, surgical instruments such as forceps, scalpels, surgical needles, sutures, and clamps of various designs, gauze pads of various construction, and surgical sponges of various materials, design, and construction. Surgical teams have implemented procedures to try to ensure that all objects are removed from the human body prior to closing the surgical field and sending the patient to recovery.
The primary method of tracking surgical objects involves manual counting of objects prior to and during surgery, and recounting them as they are recovered from the surgical field. A third count is also preferably taken to recheck the results. The count of objects introduced into the surgical field must obviously equal the count of objects recovered from the surgical field at the end of the surgical procedure.
This practice is, however, prone to human error as miscounts can occur. In such cases, surgical instruments, gauze pads, sponges, or other surgical objects may be left in the body. Alternatively, used gauze pads, sponges, or other similar objects may stick together, and result in a miscount such that the surgeon believes an object has been left in the body, when in fact none has been.
In the event an object is left in the body, physiological foreign body responses can lead to infection and death, and movement of objects such as clamps can lead to physical damage in surrounding organs, also leading to sepsis and death. Hence, accurate accounting of surgical objects is critical; not only from a patient safety standpoint, but also from a liability standpoint as such instances often result in malpractice law suits regardless of patient outcome.
To further complicate this situation, first responders must often pack wounds with gauze, sponges, or other objects during stabilization, triage, and transit to an emergency room before handing the patient off to physicians for further treatment. Particularly in cases of multiple traumas, where triage protocol dictates focusing on immediate treatment of one area of the body while simply stabilizing other wounds, confusion can result. Examples of such cases include multiple gun-shot wounds, multiple shrapnel wounds, and others. In this situation, attending physicians may also not receive an accurate accounting of objects placed in the body and overlook items placed by first responders.
Szymaitis (U.S. Pat. No. 5,456,718) describes an apparatus for detecting objects within the human body. A strip, when exposed to an alternating electromagnetic field, causes a detectable change in the applied field. The device includes a tagging strip and a hand-held excitation/detector system.
The device requires the use of non-magnetic surgical tables. In addition, false positives are possible due to stray fields produced by other equipment in the surgical suite, and therefore a pre-scan detection of undesired signals, as well as a method providing for their cancellation, may be required.
The conducting strips embedded in the tags work optimally only under certain geometric conditions. However, multiple folding of such strips may occur when, for example, sponges are packed in the body cavity, altering the optimal geometry for the tagging strips to work effectively. Further, the range of sizes and configurations of surgical devices may provide a further impediment to effective use of the tagging strips as the response the tagging strips create in the applied field is dependent on the length of the strips. This may be an issue particularly in smaller surgical objects that are most prone to being overlooked in the body.
Another method to localize items in the body uses X-rays. However, post-operative x-ray examination is not routine as it generally unnecessarily exposes patients to ionizing radiation, and also increases the cost of procedures.